Bihar Board Class 12 Chemistry preparation is easier to plan than most students think, because the BSEB Inter Chemistry paper is predictable. Half of the 70 theory marks are objective, drawn from NCERT facts and small calculations. The other half rewards name reactions, organic conversions, numericals from Solutions, Electrochemistry and Chemical Kinetics, and a few inorganic explanations. This guide lists the NCERT Class 12 Chemistry chapters, the name reactions you must know, the numerical types that repeat, how to write organic conversions, and a 60-day plan for the 2027 exam.
BSEB Inter Chemistry exam pattern: 70 theory, 30 practical
The Bihar Board Class 12 Chemistry paper typically carries 70 marks for theory and 30 marks for practical. In recent years the theory paper has had two sections. Section A is objective: around 70 MCQs are printed and you answer 35 on the OMR sheet, one mark each. Section B is subjective: 2-mark short-answer questions with internal choice and 5-mark long-answer questions with internal choice, adding up to the remaining 35 marks. The paper lasts 3 hours 15 minutes with 15 minutes of reading time.
Confirm the counts from the latest Bihar Board Inter Chemistry model paper on biharboardonline.bihar.gov.in. The practical carries 30 marks, so do not neglect the lab record, the viva and the salt analysis; that is almost a third of the subject in a place where careful students typically do well.
Bihar Board Inter Chemistry chapter weightage: NCERT Class 12 chapters
The BSEB Class 12 Chemistry syllabus follows the NCERT Class 12 Chemistry textbook. In recent papers the organic chapters have typically carried the largest share, roughly two-fifths, the physical chapters roughly a third, and the inorganic chapters the rest. These are rough shares, not fixed tables. Confirm the current chapter list in the official syllabus, since older chapters such as The Solid State, Surface Chemistry, The p-Block Elements, Polymers and Chemistry in Everyday Life may still appear in the BSEB edition of the textbook your school uses.
The core chapters, grouped the way the paper tests them:
- Physical: Solutions (concentration terms, Raoult's law, colligative properties), Electrochemistry (cell notation, Nernst equation, Kohlrausch law, Faraday's laws), Chemical Kinetics (rate law, order, integrated rate equations, half-life, Arrhenius equation).
- Inorganic: The d- and f-Block Elements (electronic configuration, oxidation states, colour, magnetism, lanthanoid contraction, potassium dichromate and permanganate) and Coordination Compounds (IUPAC naming, Werner theory, isomerism, valence bond theory, crystal field splitting).
- Organic: Haloalkanes and Haloarenes (SN1 and SN2, name reactions), Alcohols, Phenols and Ethers (preparation, acidity of phenol, Williamson synthesis), Aldehydes, Ketones and Carboxylic Acids (nucleophilic addition, name reactions, tests), Amines (basicity, diazonium salts) and Biomolecules (carbohydrates, proteins, vitamins, nucleic acids).
- Solutions, Electrochemistry, Chemical Kinetics, Coordination Compounds and Aldehydes, Ketones and Carboxylic Acids typically supply the most subjective questions.
BSEB 12th Chemistry objective questions: a 35-mark strategy
Bihar Board Chemistry objective questions are mostly direct: the unit of molar conductivity, the order of a reaction from its unit of rate constant, the oxidation state of Cr in dichromate, the IUPAC name of a complex, the reagent in a named reaction, which vitamin is water-soluble, the coordination number in a given complex, the product of a given reaction. Because around 70 are printed and 35 are counted, skip anything that needs a long calculation and pick the sure ones first.
Prepare from three sources inside NCERT: the chapter summary boxes, the in-text questions, and the tables (oxidation states, electrode potentials, pKa values, reagent lists). Make 25 to 30 one-liners per chapter. Practise the objective section as a separate 60-minute activity at least twice a week in the last month. A short daily test on the Bihar Board syllabus, such as the Daily Board Dose in Myrix Learn, is a convenient way to keep this recall fresh.
On the OMR, darken one circle fully with a ballpoint pen, mark exactly 35, and check the question number against the row before darkening. Keep ten minutes at the end for this check.
Bihar Board 12th Chemistry name reactions list
Name reactions appear in both halves of the paper: as a one-line objective question (which reagent, which product) and as a 2-mark subjective question (write the reaction with equation). Learn each with reactant, reagent and product written as a single line, and revise the list twice a week. The ones that have appeared most often in recent years are:
- Haloalkanes and Haloarenes: Finkelstein reaction, Swarts reaction, Wurtz reaction, Wurtz-Fittig reaction, Fittig reaction, Sandmeyer reaction, Gattermann reaction.
- Alcohols, Phenols and Ethers: Williamson synthesis, Kolbe's reaction, Reimer-Tiemann reaction, acid-catalysed hydration of alkenes, oxidation of alcohols with PCC.
- Aldehydes, Ketones and Carboxylic Acids: Rosenmund reduction, Stephen reaction, Etard reaction, Gatterman-Koch reaction, Clemmensen reduction, Wolff-Kishner reduction, Aldol condensation, Cannizzaro reaction, Hell-Volhard-Zelinsky reaction, Tollens and Fehling tests.
- Amines: Hoffmann bromamide degradation, Gabriel phthalimide synthesis, Carbylamine reaction, diazotisation, coupling reaction with phenol.
- For each reaction, be able to write the mechanism type in one phrase (nucleophilic addition, electrophilic substitution, SN1 or SN2) because 2-mark questions sometimes ask for it.
BSEB Chemistry numericals: molarity, Nernst equation and rate constants
Numericals come almost entirely from the three physical chapters, and the same types repeat. From Solutions: molarity, molality and mole fraction conversions, relative lowering of vapour pressure, elevation of boiling point and depression of freezing point, osmotic pressure and molar mass, and the van't Hoff factor. From Electrochemistry: cell EMF from standard potentials, the Nernst equation at 298 K using 0.059/n, molar conductivity and Kohlrausch law, and mass deposited from Faraday's laws. From Chemical Kinetics: rate from concentration changes, the first-order integrated equation with log, half-life of a first-order reaction, and activation energy from the Arrhenius equation with two temperatures.
Write every numerical in four lines: given data with units, formula, substitution, answer with unit. Step marking means the formula and substitution earn credit even when the log table slips. Keep a one-page formula sheet for each of the three chapters, including the constants (R = 8.314 J per mol K, F = 96500 C per mol, 0.059 V at 298 K), and rewrite it from memory weekly. The AI tutor in Myrix Learn can explain a stuck Nernst or half-life problem from a photo in Hindi, using the NCERT method.
Organic conversions: how to write them for full marks
A conversion question gives a starting compound and a target and asks for the route, for example ethanol to ethanoic acid, benzene to aniline, propanone to propene, or phenol to salicylaldehyde. Most BSEB conversions need one to three steps and use the name reactions above. Write each step on its own line with the reagent and condition written above the arrow, and name the intermediate. If you know the reaction but not the exact condition, write the reagent anyway; a correct reagent with a vague condition still earns part of the step.
Make a conversion chart per functional group: how to go from alkyl halide to alcohol, alcohol to aldehyde, aldehyde to acid, acid to amide, amide to amine, and benzene to each monosubstituted derivative. Practise twenty conversions a week from the NCERT intext and exercise questions. Also learn the distinguishing tests (Tollens, Fehling, iodoform, Lucas, Hinsberg) because 2-mark questions often ask you to distinguish two compounds.
Bihar Board 12th Chemistry 60 day plan
This Bihar Board 12th Chemistry 60 day plan assumes about two hours of Chemistry per day and one longer sitting on Sunday. Numericals and name reactions are revised throughout, not only in their own blocks.
- Days 1 to 8: Solutions and Electrochemistry. Formula sheets, NCERT examples, 30 one-liners per chapter, five numericals a day.
- Days 9 to 14: Chemical Kinetics. Integrated rate equations, half-life, Arrhenius problems, graphs for zero and first order.
- Days 15 to 22: Haloalkanes and Haloarenes, Alcohols, Phenols and Ethers. Name reactions on flash cards, SN1 versus SN2, ten conversions a day.
- Days 23 to 32: Aldehydes, Ketones and Carboxylic Acids, Amines. The largest name reaction set; distinguishing tests; diazonium chemistry.
- Days 33 to 40: The d- and f-Block Elements and Coordination Compounds. Oxidation state trends, dichromate and permanganate preparations, IUPAC naming and isomerism drills.
- Days 41 to 46: Biomolecules plus any remaining chapters in your BSEB syllabus (Solid State, Surface Chemistry, p-Block, Polymers, Chemistry in Everyday Life if listed).
- Days 47 to 54: Four full model or previous-year papers, one every second day, with an error log and re-tests of weak chapters on alternate days.
- Days 55 to 60: Formula sheets, name reaction list and conversion charts only, one objective set of 35 questions daily. Revise practical viva questions. Sleep properly in the last three days.
Common mistakes in the BSEB Class 12 Chemistry paper
Writing a name reaction without the reagent, leaving the unit off a numerical answer, confusing molarity with molality, forgetting to balance the cell reaction before applying the Nernst equation, and naming complexes with the ligands in the wrong order. Attempting both options of an internal choice is another common loss, because normally only the first attempt is evaluated. Order the paper: objective first in about 60 minutes, then 2-mark questions, then 5-mark questions, and keep ten minutes for the OMR check.
Studying from guess papers instead of the NCERT text also costs marks, because BSEB questions and their expected answers follow NCERT wording. Myrix Learn offers chapter-wise practice tests on the Bihar Board pattern in Hindi and English and spaced revision of the mistakes you make in them. It costs ₹99 for the first month and then ₹297/month, and students who complete 10 study days in a month get 25% of that month's fee back as a study reward (50% after 15 study days). Offline mode works when the network is weak.